Fuel and the process of producing fuel from lignocellulose.



\ cairn a" Marconi/r F, EWEN AND GEORGE H. ToMLINsoN, or CHICAGO, ILLINOIS, ASSIGNORS 'IO STANDARD ALCOHOL COMPANY, MAINE.

OF NEW YORK, N. Y., A CORPORATION OF 'FUEL AND THE PROCESS OF PRODUCING FUEL FBOM LIGNOCELLULOSE.

i ,oaasoi.

Ito-Drawing.

Specification of Letters Iatent.

Patented July 16,1912.

Application filed November 12, 1910. Serial No. 592,062.

To (ZZZ re/mit may cOIMftZWL 3e it known that we, MALCOLM F. Ewen,

"a citizen of the United States, and GEORGE H. TOMLINSON, a subject of the -King of England, residing atClucago, in the county of (look and State of Illinois, have invented .a cortain newand useful Improvement in the same .in connection with the production of fermentable sugar from such ligno-cellulose.

The treatment of such lig-no-cellulose for the extraction ofsugar therefrom consists generally of first putting the ligno-cellulose in a digester with a limited amount of water and acid and under a proper degree of heat and pressure and then subjecting the prod not to some kind of a diffusion process for the extraction of the sugar formed by the first part of the. process. These operations quite commonly leave the residue of the ligno-cellulose in such state or condition that it is unfit for fuel, being charged with a quantity of water and of such nature that the practical extraction of that water is'im possible. Moreover, in such operations the coinminuted ligno-cellulose not infrequently become of a nature unfitting it for fuel. If, however, the digestingprocess-be carried on in" such a way as to cause the formation of the sugar while at the same time changing the texture of the comminuted lignocellulose so as to make-it hard or granular or so as to form its own filtering bed, the

- loose condition.

1 in a loose state or have the water practically' taken from it so as-to be fit for fucl'in its A suitable hydrolyzing bath for the purpose of this invention may be prepared by thoroughly mixing with sawdust or other cellulosic raw material such proportion of a hydrolyzing acid, for example sulfuric acid, as will result in an acid'concentration "in the sawdust of 0.2 to 0.5 per cent. The

acidified mixture, which should contain less moisture than is required for its saturation and should be therefore in a permeable and absorptive condition, is then digested in presence of steam under suitable pressure, say 60 to 90 pounds, until the ferment-able sugars are formed. The matter is one of the highest importance in the operation of such .plants, because the production of fermentable sugar or alcohol from ligno-bellrilose involves the handling of vast quantities of such ligno-cellulose because of the rela tively small quantity of sugar yielding con stituents therein contained, and the use of enormous quantities of steamand power for the various operations required. To operate the process or carry out the same in such a way as to produce, with a minimum amount of difficulty, a maximum amount of good fuel from the residue, will doubtless result in great economies, and such economies are essential to' successful operation.

The nature of the material as it comes from the digester may be made clear by contrasting it with the condition of the sawdust, which is a convenient form of comminutcd ligno-cellulose, as it went into the digester. The sawdust is soft, tends to absorb moisture in a filtering funnel, tends to hold the Water back, and, when saturated,

tends to cling'together in a mass. The material as it comes from the digester when treated as above suggested, is, in its response to water, more like sand than sa lvdust. Its particles are hardenedand it does not tend to hold or retain any considerable amount of water. This, in the first place, permits a stream of water to be run or forced through the digester product in the diffusion battery,

not admit of the free passage of water and;

the easy extraction of suchwater in a drying process, then the material Will be practically unfit for fuel. The material so prepared in the digester, according to our process, is put into the ordinary form of diffusion batter and 'a large quantity of water sent theret rough, with the result that the sugar is dissolved out of the digester product and-carried into atank for subsequent freely treatment. The residue is discharged from the diffusion battery, and, preferably, conveyed in such manner as to permit the major partofthe water to drain away. The residue still actively charged with water is now squeezed in any desired manner, as, for example, in a cylindrical press;'whereupon it is found that the water is so fully ex- -tracted,-even by large presses, where large. quantities of the material are treated, that it is quite fit for fuel. The condition of this material when itleaves the digester is such that .it forms a kind of filtering bed, or selffilterifi mass, through which the water material derived from the digester and the diffusion battery which makes itcomn1er-- cially practicable to extract the Water so that the material can be used for fuel. It

T will be' understood that one thing which 'sawd'ust should be kept steadily in motion ws, and it is this character of the lfrom the time it enters the digester until it is placed Within reach of the furnace, for otherwise vast storage areasor bins have to be provided and the materials under consideration, when once'they come to rest in masses of any considerable size, are extremely diflicult to again start in motion. They tend to pack and remain fixed in position.

-VVe claim 1. As a new article of manufacture suitable for use as a fuel, a product derived from comminuted ligno-cellulose by the action of a hydrolyzing agent under heat and pres,- sure,,with subsequent extraction of its soluble constituents, said product consisting of relatively hard, granular, and nomabsorptive particles of insoluble cellulosic material, freed fromexc'ess Water. V

, 2.'The process of producing a fuel from water.

MALCOLM F. EWICN. GEORGE II. TOMLINSUN. WVitnesses ERNEsrS. BALL, A. O.. WENTE.

Copiel 0!. this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.

cornminuted ligiio-cellulose, which consists 

